US20120040100A1 - Solution deposition planarization method - Google Patents

Solution deposition planarization method Download PDF

Info

Publication number
US20120040100A1
US20120040100A1 US13/168,093 US201113168093A US2012040100A1 US 20120040100 A1 US20120040100 A1 US 20120040100A1 US 201113168093 A US201113168093 A US 201113168093A US 2012040100 A1 US2012040100 A1 US 2012040100A1
Authority
US
United States
Prior art keywords
solution
substrate
concentration
rms
oxide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/168,093
Inventor
Vladimir Matias
Christopher J. Sheehan
Jon Fredrick Ihlefeld
Paul Gilbert Clem
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Technology and Engineering Solutions of Sandia LLC
Los Alamos National Security LLC
Original Assignee
Los Alamos National Security LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Los Alamos National Security LLC filed Critical Los Alamos National Security LLC
Priority to US13/168,093 priority Critical patent/US20120040100A1/en
Assigned to LOS ALAMOS NATIONAL SECURITY, LLC reassignment LOS ALAMOS NATIONAL SECURITY, LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MATIAS, VLADIMIR, SHEEHAN, CHRISTOPHER J
Assigned to U.S. DEPARTMENT OF ENERGY reassignment U.S. DEPARTMENT OF ENERGY CONFIRMATORY LICENSE (SEE DOCUMENT FOR DETAILS). Assignors: LOS ALAMOS NATIONAL SECURITY
Publication of US20120040100A1 publication Critical patent/US20120040100A1/en
Assigned to SANDIA CORPORATION reassignment SANDIA CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CLEM, PAUL GILBERT, IHLEFELD, JON FREDRICK
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N60/00—Superconducting devices
    • H10N60/01—Manufacture or treatment
    • H10N60/0268—Manufacture or treatment of devices comprising copper oxide
    • H10N60/0296—Processes for depositing or forming copper oxide superconductor layers
    • H10N60/0576—Processes for depositing or forming copper oxide superconductor layers characterised by the substrate
    • H10N60/0632—Intermediate layers, e.g. for growth control

Definitions

  • the present invention relates generally to a solution deposition planarization method for providing a substrate with a very smooth surface.
  • HTSCCs high temperature superconducting coated conductors
  • Flexible substrates are light, and they offer other advantages of having large areas with small volumes, varying form factors, and a reduction of manufacturing costs when materials are processed roll to roll. Flexible substrates, however, may not have the surface smoothness needed for optimal performance.
  • the preparation of practical, layered HTSCCs, for example, requires a very smooth surface for deposition of the superconductor.
  • Ion-beam-assisted deposition (IBAD) texturing is used to create a biaxially textured (crystal-aligned) MgO layer for epitaxial growth of a highly aligned superconductor.
  • the biaxially-textured MgO layer must be very thin, so an extremely smooth substrate is needed for the MgO layer.
  • an inexpensive and fast process to produce smooth substrates for IBAD-MgO textured layers is needed.
  • Mechanical polishing provides a smooth enough substrate surface but may not be practical for long lengths and/or large areas because mechanical polishing is expensive and time consuming.
  • Electropolishing provides a fast process for preparing smooth substrates, but is limited to a few metal alloys, requires expensive starting materials, and generates toxic acid waste.
  • An efficient and inexpensive process that transforms any rough substrate surface into a surface smooth enough for an IBAD-MgO textured layer is desirable.
  • a surface roughness RMS of 1 nm or less (on a 5 ⁇ 5 ⁇ m scale) is required for high quality IBAD-MgO layer.
  • An object of the invention is to provide an inexpensive and efficient process for substrate planarization that does not involve polishing but results in a surface that is smooth enough for an IBAD-MgO textured layer for subsequent deposition thereon of a superconductor.
  • the present invention provides a process for planarizing a substrate.
  • the process includes providing a substrate having a surface roughness of at least 3 nm RMS (root mean square).
  • the substrate may have a much rougher surface, such as surface roughness of at least 20 nm RMS.
  • the process also includes providing a first solution having a first concentration of yttrium oxide precursor in a solvent, and applying a coating of the solution to the rough surface.
  • the coated substrate is heated under conditions sufficient to evaporate the solvent and convert the solution of yttrium oxide precursor to a layer of yttrium oxide on the substrate.
  • the steps of applying a coating of the first solution and then heating are repeated to provide a plurality of layers of yttrium oxide, including a surface roughness less than 3 nm RMS but greater than 1 nm RMS (root mean square) on a 5 by 5 ⁇ m scale
  • a second solution comprising a second concentration of yttrium precursor is also provided, the second concentration of the yttrium precursor being lower than the first concentration, and a coating of the second solution is applied on the layer of yttrium oxide.
  • the now coated substrate is heated to evaporate the solvent and leave another layer of yttrium oxide on the substrate.
  • the steps of applying a coating of the second solution and heating are repeated until a planarized substrate having plurality of layers of yttrium oxide deposited thereon is produced with a surface roughness less than 1 nm RMS.
  • the above method above can be adapted by replacing yttrium oxide with another metal oxide.
  • rare earth metal oxides may be deposited.
  • the invention also includes a method for preparing a layered article.
  • the method includes providing a substrate having a rough surface, providing a first solution comprising a first concentration of a metal oxide precursor in a solvent, applying a coating of the solution to the rough surface, heating the coated substrate under conditions sufficient to evaporate the solvent and convert the solution of metal oxide precursor to a layer of metal oxide on the substrate, repeating the steps of applying a coating of the first solution to the rough surface and heating, thereby forming a plurality of layers of metal oxide on the substrate.
  • the method also includes providing a second solution comprising a second concentration of metal oxide precursor, the second concentration lower than the first concentration, applying a coating of the second solution on the layer of metal oxide, heating the coated substrate to evaporate the solvent and leave a layer of metal oxide on the substrate, and repeating the steps of applying a coating of the second solution and heating. Then a layer of IBAD-MgO is deposited on the metal oxide.
  • FIG. 1 a shows a cross sectional view of a transmission electron micrograph (TEM) of a substrate coated with layers of yttrium oxide according to an embodiment.
  • An IBAD-MgO layer is on the topmost yttrium oxide layer, a SrTiO 3 buffer layer on the IBAD-MgO layer, and YBCO superconductor layer is on top of the IBAD-MgO layer.
  • FIG. 1 b is a higher magnification image of a portion of FIG. 1 a that shows individual layers of yttrium oxide in more detail.
  • FIG. 2 shows a plot of RMS roughness as a function of the number of SDP coatings of an embodiment process using a 0.08 M solution of yttrium oxide precursor and a 0.04 M solution of the yttrium oxide precursor.
  • FIG. 3 shows a plot of RMS roughness on a 5 ⁇ 5 micrometer area as a function of the number of SDP coatings for a 0.4 M solution of yttrium oxide precursor followed by a 0.08 M solution of the yttrium oxide precursor.
  • FIG. 4 shows a plot of MgO texture as a function of the number of SDP coatings for two solutions. Solid symbols represent average out-of-plane texture and open symbols represent the in-plane texture.
  • FIG. 5 a shows a plot of out of plane texture of IBAD-MgO vs. RMS roughness
  • FIG. 5 b shows a ploy of in plane texture of IBAD-MgO vs. RMS roughness
  • the IBAD-MgO is deposited on (i) a substrate planarized by SDP using a 0.4 M solution of yttrium acetate (black squares), (ii) a substrate planarized by SDP using a 0.08 M solution of yttrium acetate (gray squares), and (iii) a substrate planarized by SDP using a two-solution process wherein the first solution is 0.4 M yttrium acetate and the second solution is 0.08 M yttrium acetate (diamond), and (iv) a substrate planarized by mechanical polishing (open black circles).
  • the mechanically polished samples data is from Matias et al. in Mater. Res. Soc. Symp. Proc., Barnes et al. editors, vol. 1001E, Warrendale, Pa., 2007, No. 100′-M04-02.
  • the in plane texture is superior for the process involving the two solutions.
  • the invention relates to a chemical solution deposition process to planarize a rough substrate surface efficiently, inexpensively, and in long lengths of substrate.
  • layers are added that are smoother than the underlying rough substrate surface.
  • the method is sometimes referred herein as Solution Deposition Planarization (SDP).
  • SDP Solution Deposition Planarization
  • the method has been shown to produce a surface roughness under 1 nm RMS starting with a substrate surface that is rougher by two orders of magnitude.
  • the additional layers that planarize the substrate may also serve the dual purpose as an interdiffusion barrier.
  • An aspect of this invention applies to the formation of a plurality of layers of yttrium oxide on a rough substrate surface to planarize the surface.
  • This involves applying a coating of a first solution of yttrium oxide precursor to the rough surface.
  • the precursor may be yttrium acetate, or some other yttrium containing precursor that converts to the oxide upon heating in an oxidizing environment.
  • the coated substrate is heated under conditions sufficient to evaporate the solvent and convert the solution of yttrium oxide precursor to a layer of yttrium oxide on the substrate.
  • These steps of applying a coating of the first solution and heating are repeated to provide a plurality of layers of yttrium oxide, the plurality with a surface roughness greater than 1 nm RMS.
  • the surface roughness is preferably greater than 1 nm RMS but less than 5 nm RMS, or less than 4 nm RMS, or less than 3 nm RMS, or less than 2 nm RMS.
  • a coating of a second solution is then applied to the topmost yttrium oxide layer, the second solution having a concentration of the yttrium oxide precursor that is less than the concentration of precursor in the first solution.
  • the substrate is heated to evaporate the solvent and leave a second layer of yttrium oxide.
  • the steps of applying a coating of the second solution and heating are repeated until a planarized substrate having plurality of layers of yttrium oxide deposited thereon is produced, the surface roughness now less than 1 nm RMS. It was found that when the concentration of yttrium oxide precursor is less for the second solution that the first, after forming a plurality of layers on the substrate, a surface roughness less than 1 nm RMS, less than 0.9 nm RMS, less than 0.8 nm RMS, less than 0.7 nm RMS, and even less than 0.6 nm RMS was achieved.
  • a surface roughness between 0.6 nm RMS and 0.5 nm RMS was realized using this method when the concentration of the first solution was 0.4 M and the concentration of the second solution was 0.08 M when the yttrium oxide precursor was yttrium acetate.
  • the method is applied to substrates with rough surfaces.
  • the surface has a surface roughness of at least 20 nanometers (nm) RMS (root-mean-squared).
  • the surface roughness is at least 30 nm RMS.
  • the surface roughness is at least 40 nm RMS.
  • the surface roughness is at least 50 nm RMS.
  • the substrates may be metal substrates, ceramic substrates, or some other substrate having a rough surface.
  • a metal or metal alloy such as a hastelloy may be a substrate.
  • Silicon may be a substrate.
  • a stainless steel may be a substrate.
  • silica may be a substrate.
  • alumina may be a substrate.
  • silicon nitride may be a substrate.
  • the substrates are flexible.
  • the substrates should be long, at least 5 meters in length.
  • Substrates having a length greater than 10 meters, greater than 25 meters, greater than 50 meters, greater than 100 meters, greater than 500 meters, greater than 1000 meters, greater than 5000 meters, greater than 10,000 meters, greater than 100,000 meters, greater than 250,000 meters, greater than 500,000 meters, greater than 1,000,000 meters, and so on, may be prepared using the present method.
  • the invention does not involve polishing the substrate surface to eliminate surface roughness.
  • the invention applies to substrates with rough surfaces that have not been subjected to mechanical polishing.
  • the rough substrate surface prior to planarization is contoured with many peaks and valleys.
  • the surface tension of the liquid planarizes the contoured surface resulting in thicker regions over the valleys and thinner regions over the peaks.
  • the coating shrinks following the original substrate contours, with a decrease in roughness compared to the underlying substrate. By repeating the process a number of times, further reduction in roughness is obtained.
  • Hastelloy C-276 metal tape 0.1 mm thick, was used as the substrate.
  • the metal tape was 10 mm wide and about 5 meters long.
  • the starting roughness was 33 nm RMS (50 micrometer scale). In another embodiment, the starting roughness was 21 nm (5 micrometer scale).
  • Solution Deposition Planarization (SDP) coatings of yttria were done using dip coating in a continuous tape loop coater where the tape is dipped into a bath and then heated repeatedly.
  • SDP Solution Deposition Planarization
  • the dip coating bath included a submerged idler and the tape exits the free liquid surface away from the idler surface.
  • the tape pull speed was 200 mm/min. The tape then entered a flow-controlled environment during the solvent drying stage to reduce turbulence.
  • Solutions of 0.08 M and 0.40 M concentration were prepared by mixing yttrium (III) acetate tetrahydrate in a solvent of methanol and diethanolamine. The solutions were filtered using a 0.22 micrometer polytetrafluoroethylene syringe filter prior to use.
  • Atomic force microscopy (AFM) and profilometry were used to measure the surface roughness and thin film thickness after every 5 SDP coatings.
  • AFM scans were taken over 5 ⁇ 5 micrometer and 50 ⁇ 50 micrometer areas for 5 points and results were averaged.
  • a second order flattening procedure was used to remove the background height in the AFM scans.
  • IBAD-MgO a biaxially-textured layer of IBAD-MgO was applied. This procedure took place in a vacuum chamber. Tape samples from the SDP were spliced together. All the depositions were done in one IBAD pass and run. An ion beam of Ar at 1000 volts (V) was used for assist at 45° to the substrate normal. MgO was deposited by electron-beam sublimation at a rate of 0.45 nm/s. The MgO deposition time was 50 seconds. A homoepitaxial MgO layer of 150 nm was deposited in situ at a rate of 8 nanometers per second (nm/s) at approximately 500° C. Samples were analyzed by x-ray diffraction to determine the mosaic spreads.
  • FIG. 1 a - b shows cross sectional transmission electron microscope (TEM) images of the Hastelloy tape after 15 SDP coatings of yttrium oxide, a layer of IBAD-MgO on the yttrium oxide, and YBCO on the IBAD-MgO layer.
  • the planarization effect is noticeable, particularly in FIG. 1 b where the individual yttrium oxide layers are more clearly separated from each other.
  • the SDP is tolerant of substrate defects as it encapsulates them and shows no sign of the defect at the interface with the IBAD-MgO layer.
  • the RMS roughness over a 5 ⁇ 5 micrometer area was used to characterize the surfaces at each stage of deposition.
  • the data after sequential coatings are shown in FIG. 2 for the two different solutions, 0.08 M and 0.4 M.
  • the lower molarity solution has the slower planarization effect of the two solutions but its effectiveness persists for more passes than the higher molarity solution, which appears to saturate at a roughness of about 1.5 nm RMS.
  • the two solutions yield approximately the same 5 micrometer roughness. However, 15 coatings of the 0.08 M solution is still rougher on this scale than only 5 coatings of the 0.4 M solution.
  • t fin is the thickness that remains after pyrolysis and t init is the thickness of the last liquid state that retains a flat surface.
  • the remaining roughness (R fin ) is then
  • R fin R init s
  • R init is the initial roughness. If there were no shrinkage, the resulting surface would be perfectly flat with no roughness. From this simple model, RMS roughness is R q wherein
  • n is the number of coatings and R 0 is the initial RMS roughness of the substrate.
  • R 0 is the initial RMS roughness of the substrate.
  • the dashed lines in FIG. 2 are the fits to the initial slopes of the data for both solutions. For the 0.4 M solution, the data immediately fall off the fitted curve. For the 0.08 M solution, the data deviate from the fit at a higher number of coatings.
  • the roughness of the SDP is limited by the residual roughness of each solution deposited film.
  • AFM images indicate a granular structure to the films that is dependent on the film thickness.
  • the ratio of the film thicknesses is approximately 5, which is close to the ratio of the molarities of the two solutions.
  • the data show the residual roughness appears to be 1.5 nm or about 2.5% of the film thickness. The same relative fraction extrapolated to the 0.08 M solution would yield a residual roughness of about 0.4 nm.
  • FIG. 4 is a plot of MgO texture as a function of the number of SDP coatings for the two solutions.
  • Square symbols represent average out-of-plane texture and circles represent in-plane texture.
  • the inset shows the out-of-plane texture as a function of RMS roughness together with the data taken from Matias et al. in Mater. Res. Soc. Symp. Proc., edited by Barnes et al., vol. 1001E, Warrendale, Pa., 2007, No. 1001-M04-02.
  • the SDP prepared substrates were used for creating IBAD templates for superconducting coated conductors.
  • a layer of YBa 2 Cu 3 O 7 (YBCO) of 1-3 micrometers in thickness was deposited on the IBAD template.
  • YBCO deposition techniques were used successfully on these templates, including pulsed laser deposition (PLD), reactive coevaporation (RCE), and MOCVD.
  • FIG. 1 a shows a 1.2 micrometer YBCO layer deposited by PLD on the IBAD/SDP template with a SrTiO3 buffer layer.
  • the critical current, J c at 75K in self field (SF) was measured to be 2.85 MA/cm 2 .
  • Another aspect of this invention relates to other benefits that are afforded by using a rough substrate and coating with a first solution and then with a second solution.
  • a benefit relates to certain properties of an IBAD-MgO layer deposited on the topmost of the metal oxide layers. A surface roughness less than 1 nm RMS is not required.
  • FIG. 5 a shows a plot of out of plane texture of IBAD-MgO vs. RMS roughness
  • FIG. 5 b shows a plot of in plane texture of IBAD-MgO vs. RMS roughness.
  • the plots compare the in plane texture of the IBAD-MgO layers deposited on a variety of surfaces.
  • One of the surfaces is a mechanically polished substrate (open circles).
  • Another surface is formed when a 0.4 M solution of yttrium acetate was used for solution deposition planarization (red squares), and the surface roughness RMS is shown on the x-axis.
  • Another surface is formed when a 0.08 M solution of yttrium acetate was used for solution deposition planarization (gray squares), the surface roughness also shown on the x-axis.
  • the in plane texture of the IBAD-MgO layer appears to be better for the lower molarity solution, and is best when two solutions (diamond), a first solution of 0.4 M, and a second solution of 0.08 M, are used.
  • the plot also indicates that the lower molarities (0.08 M) provide a better in plane texture than the higher molarity coating (0.4 M). At higher surface roughness, the lower molarity coating is a good choice.
  • the in plane texture for IBAD-MgO deposited on yttrium oxide was best for a process wherein a first solution of 0.4 M yttrium oxide precursor (yttrium acetate, for example) was used first, and then a second solution of lower molarity (0.08 M yttrium oxide precursor, yttrium acetate).
  • the invention of solution deposition planarization may be used for smoothing substrates in long lengths with resulting RMS roughness less than 1 nm.
  • these planarized substrates can be used directly for IBAD-MgO texturing with very high quality and then for deposition of very high Jc-cuprate superconductors.
  • metal oxides besides yttrium oxide may be used instead of yttrium oxide, or in mixtures with yttrium oxide.
  • These other metal oxides include aluminum oxide, titanium oxide, zirconium oxide, hafnium oxide, and rare earth metal oxides such as erbium oxide.
  • a mixture of aluminum oxide with yttrium oxide may also be used.
  • the invention has thus far been described using two solutions of two different concentrations.
  • the method may be expanded by using three solutions of different molarities, wherein the first solution has a concentration greater than the second solution and the second solution has a concentration greater than the third solution.
  • the method can be expanded to the use of four solutions wherein the first has the highest concentration of the metal oxide precursor, the second having a lower concentration than the first solution with the same precursor, the third solution having a concentration lower than the second, and the fourth a lower concentration than the third.
  • This can be expanded for any number ‘n’ of solutions where the concentration decreases sequentially to the nth solution which has the lowest concentration of the metal oxide precursor.
  • the invention also applies the preparation of metal oxynitride coatings.
  • titanium dioxide and zirconium dioxide coatings were prepared to planarize unpolished aluminum plate to enable integrated electronics deposition atop the insulating TiO 2 or ZrO 2 top surface.
  • Solutions of 0.15 M concentration and then 0.05M concentration (a) titanium isopropoxide in isopropanol or (b) zirconium butoxide in isopropanol were subsequently dip coated, using eight layers of each concentration, dried at 300° C. for 1 minute, and subsequently annealed in air at 450° C. for 10 minutes, atop 30 cm wide aluminum plates.
  • the coatings reduced the initial 5 micron-scale roughness to less than 100 nm RMS after annealing.
  • the TiO 2 or ZrO 2 coated aluminum was subsequently used as an insulating substrate for printed electronic circuit boards, in which the deposited conductive metal traces were then electrically insulated from the rough aluminum substrate via the planarization layers.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Superconductors And Manufacturing Methods Therefor (AREA)

Abstract

A process for planarizing a substrate involves applying a coating of a first solution of yttrium oxide precursor to a rough substrate surface and heating to remove solvent and convert the yttrium oxide precursor to yttrium oxide. This is repeated with the first solution and then with the second solution. A final surface roughness less than 1 nm RMS may be obtained. In addition, a process for preparing a layered structure includes solution deposition planarization of a rough substrate using different concentrations of metal oxide precursor to provide a metal oxide surface having a surface roughness, and then depositing MgO by IBAD (ion beam assisted deposition). A benefit of a better in plane MgO texture was observed for lower molarities, and when two solutions of different concentrations was employed for coating the rough substrate prior to IBAD-MgO.

Description

    RELATED APPLICATIONS
  • This application claims the benefit of U.S. Provisional Application No. 61/359,733, entitled “Substrates for Layered Superconductors,”, filed Jun. 29, 2010, which is incorporated by reference herein.
    • STATEMENT REGARDING FEDERAL RIGHTS
  • This invention was made with government support under Contract No. DE-AC52-06NA25396 awarded by the U.S. Department of Energy. The government has certain rights in the invention.
    • FIELD OF THE INVENTION
  • The present invention relates generally to a solution deposition planarization method for providing a substrate with a very smooth surface.
    • BACKGROUND OF THE INVENTION
  • Mechanically flexible substrates for thin films are growing in popularity for electronic devices such as displays, printed circuit boards, solar cells, batteries, and high temperature superconducting coated conductors (HTSCCs). Flexible substrates are light, and they offer other advantages of having large areas with small volumes, varying form factors, and a reduction of manufacturing costs when materials are processed roll to roll. Flexible substrates, however, may not have the surface smoothness needed for optimal performance. The preparation of practical, layered HTSCCs, for example, requires a very smooth surface for deposition of the superconductor. Ion-beam-assisted deposition (IBAD) texturing is used to create a biaxially textured (crystal-aligned) MgO layer for epitaxial growth of a highly aligned superconductor. The biaxially-textured MgO layer must be very thin, so an extremely smooth substrate is needed for the MgO layer. Thus, for practical implementation of HTSCCs, an inexpensive and fast process to produce smooth substrates for IBAD-MgO textured layers is needed. Mechanical polishing provides a smooth enough substrate surface but may not be practical for long lengths and/or large areas because mechanical polishing is expensive and time consuming. Electropolishing provides a fast process for preparing smooth substrates, but is limited to a few metal alloys, requires expensive starting materials, and generates toxic acid waste.
  • An efficient and inexpensive process that transforms any rough substrate surface into a surface smooth enough for an IBAD-MgO textured layer is desirable. Generally, a surface roughness RMS of 1 nm or less (on a 5×5 μm scale) is required for high quality IBAD-MgO layer.
  • An object of the invention is to provide an inexpensive and efficient process for substrate planarization that does not involve polishing but results in a surface that is smooth enough for an IBAD-MgO textured layer for subsequent deposition thereon of a superconductor.
    • SUMMARY OF THE INVENTION
  • To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a process for planarizing a substrate. The process includes providing a substrate having a surface roughness of at least 3 nm RMS (root mean square). The substrate may have a much rougher surface, such as surface roughness of at least 20 nm RMS. The process also includes providing a first solution having a first concentration of yttrium oxide precursor in a solvent, and applying a coating of the solution to the rough surface. The coated substrate is heated under conditions sufficient to evaporate the solvent and convert the solution of yttrium oxide precursor to a layer of yttrium oxide on the substrate. The steps of applying a coating of the first solution and then heating are repeated to provide a plurality of layers of yttrium oxide, including a surface roughness less than 3 nm RMS but greater than 1 nm RMS (root mean square) on a 5 by 5 μm scale A second solution comprising a second concentration of yttrium precursor is also provided, the second concentration of the yttrium precursor being lower than the first concentration, and a coating of the second solution is applied on the layer of yttrium oxide. The now coated substrate is heated to evaporate the solvent and leave another layer of yttrium oxide on the substrate. The steps of applying a coating of the second solution and heating are repeated until a planarized substrate having plurality of layers of yttrium oxide deposited thereon is produced with a surface roughness less than 1 nm RMS.
  • The above method above can be adapted by replacing yttrium oxide with another metal oxide. For example, rare earth metal oxides may be deposited.
  • The invention also includes a method for preparing a layered article. The method includes providing a substrate having a rough surface, providing a first solution comprising a first concentration of a metal oxide precursor in a solvent, applying a coating of the solution to the rough surface, heating the coated substrate under conditions sufficient to evaporate the solvent and convert the solution of metal oxide precursor to a layer of metal oxide on the substrate, repeating the steps of applying a coating of the first solution to the rough surface and heating, thereby forming a plurality of layers of metal oxide on the substrate. The method also includes providing a second solution comprising a second concentration of metal oxide precursor, the second concentration lower than the first concentration, applying a coating of the second solution on the layer of metal oxide, heating the coated substrate to evaporate the solvent and leave a layer of metal oxide on the substrate, and repeating the steps of applying a coating of the second solution and heating. Then a layer of IBAD-MgO is deposited on the metal oxide.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
  • FIG. 1 a shows a cross sectional view of a transmission electron micrograph (TEM) of a substrate coated with layers of yttrium oxide according to an embodiment. An IBAD-MgO layer is on the topmost yttrium oxide layer, a SrTiO3 buffer layer on the IBAD-MgO layer, and YBCO superconductor layer is on top of the IBAD-MgO layer. FIG. 1 b is a higher magnification image of a portion of FIG. 1 a that shows individual layers of yttrium oxide in more detail.
  • FIG. 2 shows a plot of RMS roughness as a function of the number of SDP coatings of an embodiment process using a 0.08 M solution of yttrium oxide precursor and a 0.04 M solution of the yttrium oxide precursor.
  • FIG. 3 shows a plot of RMS roughness on a 5×5 micrometer area as a function of the number of SDP coatings for a 0.4 M solution of yttrium oxide precursor followed by a 0.08 M solution of the yttrium oxide precursor.
  • FIG. 4 shows a plot of MgO texture as a function of the number of SDP coatings for two solutions. Solid symbols represent average out-of-plane texture and open symbols represent the in-plane texture.
  • FIG. 5 a shows a plot of out of plane texture of IBAD-MgO vs. RMS roughness, and FIG. 5 b shows a ploy of in plane texture of IBAD-MgO vs. RMS roughness, wherein for both FIGURES the IBAD-MgO is deposited on (i) a substrate planarized by SDP using a 0.4 M solution of yttrium acetate (black squares), (ii) a substrate planarized by SDP using a 0.08 M solution of yttrium acetate (gray squares), and (iii) a substrate planarized by SDP using a two-solution process wherein the first solution is 0.4 M yttrium acetate and the second solution is 0.08 M yttrium acetate (diamond), and (iv) a substrate planarized by mechanical polishing (open black circles). The mechanically polished samples data is from Matias et al. in Mater. Res. Soc. Symp. Proc., Barnes et al. editors, vol. 1001E, Warrendale, Pa., 2007, No. 100′-M04-02. The in plane texture is superior for the process involving the two solutions.
    •  DETAILED DESCRIPTION
  • The invention relates to a chemical solution deposition process to planarize a rough substrate surface efficiently, inexpensively, and in long lengths of substrate. Instead of removing material to planarize a substrate having a rough surface, as a polishing method does, layers are added that are smoother than the underlying rough substrate surface. The method is sometimes referred herein as Solution Deposition Planarization (SDP). The method has been shown to produce a surface roughness under 1 nm RMS starting with a substrate surface that is rougher by two orders of magnitude. For the preparation of layered structures that support IBAD-MgO, the additional layers that planarize the substrate may also serve the dual purpose as an interdiffusion barrier.
  • An aspect of this invention applies to the formation of a plurality of layers of yttrium oxide on a rough substrate surface to planarize the surface. This involves applying a coating of a first solution of yttrium oxide precursor to the rough surface. The precursor may be yttrium acetate, or some other yttrium containing precursor that converts to the oxide upon heating in an oxidizing environment. The coated substrate is heated under conditions sufficient to evaporate the solvent and convert the solution of yttrium oxide precursor to a layer of yttrium oxide on the substrate. These steps of applying a coating of the first solution and heating are repeated to provide a plurality of layers of yttrium oxide, the plurality with a surface roughness greater than 1 nm RMS. At this stage, the surface roughness is preferably greater than 1 nm RMS but less than 5 nm RMS, or less than 4 nm RMS, or less than 3 nm RMS, or less than 2 nm RMS. Once this level of roughness is achieved, a coating of a second solution is then applied to the topmost yttrium oxide layer, the second solution having a concentration of the yttrium oxide precursor that is less than the concentration of precursor in the first solution. The substrate is heated to evaporate the solvent and leave a second layer of yttrium oxide. The steps of applying a coating of the second solution and heating are repeated until a planarized substrate having plurality of layers of yttrium oxide deposited thereon is produced, the surface roughness now less than 1 nm RMS. It was found that when the concentration of yttrium oxide precursor is less for the second solution that the first, after forming a plurality of layers on the substrate, a surface roughness less than 1 nm RMS, less than 0.9 nm RMS, less than 0.8 nm RMS, less than 0.7 nm RMS, and even less than 0.6 nm RMS was achieved. In an embodiment, a surface roughness between 0.6 nm RMS and 0.5 nm RMS was realized using this method when the concentration of the first solution was 0.4 M and the concentration of the second solution was 0.08 M when the yttrium oxide precursor was yttrium acetate.
  • The method is applied to substrates with rough surfaces. By rough, the surface has a surface roughness of at least 20 nanometers (nm) RMS (root-mean-squared). In some embodiments, the surface roughness is at least 30 nm RMS. In some embodiments, the surface roughness is at least 40 nm RMS. In other embodiments, the surface roughness is at least 50 nm RMS.
  • The substrates may be metal substrates, ceramic substrates, or some other substrate having a rough surface. In an embodiment, a metal or metal alloy, such as a hastelloy may be a substrate. Silicon may be a substrate. In an embodiment, a stainless steel may be a substrate. In another embodiment, silica may be a substrate. In another embodiment, alumina may be a substrate. In another embodiment, silicon nitride may be a substrate.
  • The substrates are flexible. For the purposes of preparing flexible layered coated superconductors, the substrates should be long, at least 5 meters in length. Substrates having a length greater than 10 meters, greater than 25 meters, greater than 50 meters, greater than 100 meters, greater than 500 meters, greater than 1000 meters, greater than 5000 meters, greater than 10,000 meters, greater than 100,000 meters, greater than 250,000 meters, greater than 500,000 meters, greater than 1,000,000 meters, and so on, may be prepared using the present method. There is in fact, no limit to the length of the substrate having a rough surface that can be used with the present method.
  • It should be understood that the invention does not involve polishing the substrate surface to eliminate surface roughness. The invention applies to substrates with rough surfaces that have not been subjected to mechanical polishing.
  • The rough substrate surface prior to planarization is contoured with many peaks and valleys. Upon coating with a liquid solution, the surface tension of the liquid planarizes the contoured surface resulting in thicker regions over the valleys and thinner regions over the peaks. After drying and pyrolysis, the coating shrinks following the original substrate contours, with a decrease in roughness compared to the underlying substrate. By repeating the process a number of times, further reduction in roughness is obtained.
  • In an embodiment, Hastelloy C-276 metal tape, 0.1 mm thick, was used as the substrate. In an embodiment, the metal tape was 10 mm wide and about 5 meters long. In an embodiment the starting roughness was 33 nm RMS (50 micrometer scale). In another embodiment, the starting roughness was 21 nm (5 micrometer scale).
  • Solution Deposition Planarization (SDP) coatings of yttria (Y2O3) were done using dip coating in a continuous tape loop coater where the tape is dipped into a bath and then heated repeatedly. A diagram of the apparatus can be found in FIG. 3 of Hänisch et al. entitled “Stacks of YBCO Films Using Multiple IBAD Templates,” IEEE Transactions on Applied Superconductivity, June 2007, vol. 17, no. 2, pp. 3577-3580, hereby incorporated by reference. The dip coating bath included a submerged idler and the tape exits the free liquid surface away from the idler surface. The tape pull speed was 200 mm/min. The tape then entered a flow-controlled environment during the solvent drying stage to reduce turbulence. Subsequently, yttria conversion and hydrocarbon oxidation took place in a 22 mm OD, 610 mm long, quartz tube at a temperature of 515±10° C. Dry compressed air flow at 11.8 L/min ensured sufficient oxidation and removal of byproducts within the tube.
  • Multiple passes were performed by continuous operation of the coater. Solutions of 0.08 M and 0.40 M concentration were prepared by mixing yttrium (III) acetate tetrahydrate in a solvent of methanol and diethanolamine. The solutions were filtered using a 0.22 micrometer polytetrafluoroethylene syringe filter prior to use.
  • Atomic force microscopy (AFM) and profilometry were used to measure the surface roughness and thin film thickness after every 5 SDP coatings. AFM scans were taken over 5×5 micrometer and 50×50 micrometer areas for 5 points and results were averaged. A second order flattening procedure was used to remove the background height in the AFM scans.
  • Following SDP, a biaxially-textured layer of IBAD-MgO was applied. This procedure took place in a vacuum chamber. Tape samples from the SDP were spliced together. All the depositions were done in one IBAD pass and run. An ion beam of Ar at 1000 volts (V) was used for assist at 45° to the substrate normal. MgO was deposited by electron-beam sublimation at a rate of 0.45 nm/s. The MgO deposition time was 50 seconds. A homoepitaxial MgO layer of 150 nm was deposited in situ at a rate of 8 nanometers per second (nm/s) at approximately 500° C. Samples were analyzed by x-ray diffraction to determine the mosaic spreads. The procedure used for the MgO deposition has been described in a paper by Matias et al. entitled “Very Fast Biaxial Texture Evolution Using High Rate Ion-Beam-Assisted Deposition of MgO,” J. Mater. Res., January 2009, vol. 24, p. 125-129, incorporated by reference herein.
  • FIG. 1 a-b shows cross sectional transmission electron microscope (TEM) images of the Hastelloy tape after 15 SDP coatings of yttrium oxide, a layer of IBAD-MgO on the yttrium oxide, and YBCO on the IBAD-MgO layer. The planarization effect is noticeable, particularly in FIG. 1 b where the individual yttrium oxide layers are more clearly separated from each other. Furthermore, particularly in FIG. 1 b, one can see that the SDP is tolerant of substrate defects as it encapsulates them and shows no sign of the defect at the interface with the IBAD-MgO layer.
  • The RMS roughness over a 5×5 micrometer area was used to characterize the surfaces at each stage of deposition. The data after sequential coatings are shown in FIG. 2 for the two different solutions, 0.08 M and 0.4 M. The lower molarity solution has the slower planarization effect of the two solutions but its effectiveness persists for more passes than the higher molarity solution, which appears to saturate at a roughness of about 1.5 nm RMS. At 25 coatings, the two solutions yield approximately the same 5 micrometer roughness. However, 15 coatings of the 0.08 M solution is still rougher on this scale than only 5 coatings of the 0.4 M solution.
  • The results were analyzed using a simple model for the decrease in roughness resulting from the amount of shrinkage in each coating. The liquid layer is assumed to be perfectly flat. As the liquid evaporates and the coating shrinks into a solid and then converts to the oxide film, the films regain some of the original roughness, but diminished in magnitude. The remaining roughness can be modeled from the shrinkage of the film. Shrinkage (s) is defined as follows:

  • s=1−t fin /t init
  • where tfin is the thickness that remains after pyrolysis and tinit is the thickness of the last liquid state that retains a flat surface. The remaining roughness (Rfin) is then

  • Rfin=Rinits,
  • where Rinit is the initial roughness. If there were no shrinkage, the resulting surface would be perfectly flat with no roughness. From this simple model, RMS roughness is Rq wherein

  • Rq=R0sn
  • where n is the number of coatings and R0 is the initial RMS roughness of the substrate. The dashed lines in FIG. 2 are the fits to the initial slopes of the data for both solutions. For the 0.4 M solution, the data immediately fall off the fitted curve. For the 0.08 M solution, the data deviate from the fit at a higher number of coatings.
  • We postulate that the roughness of the SDP is limited by the residual roughness of each solution deposited film. AFM images indicate a granular structure to the films that is dependent on the film thickness. For the 0.08 M solution film thickness was measured to be 12 nm±2 nm and for the 0.4 M solution 62 nm±5 nm. The ratio of the film thicknesses is approximately 5, which is close to the ratio of the molarities of the two solutions. For the 0.4 M solution SDP, the data show the residual roughness appears to be 1.5 nm or about 2.5% of the film thickness. The same relative fraction extrapolated to the 0.08 M solution would yield a residual roughness of about 0.4 nm. In an attempt to verify our prediction, a second set of experiments was performed where we first coated with the 0.4 M solution and then with the 0.08 solution. Results are shown in FIG. 3. After 15 coatings with the 0.4 M solution of yttrium oxide precursor, the RMS roughness was reduced to 2.5 nm. Further coatings with the 0.08 solution of yttrium oxide precursor reduced the roughness to about 0.5 nm where it saturated.
  • IBAD texture measurements were performed on the series of SDP coatings with the two different molarity solutions. The resulting MgO in-plane and out-of-plane texture data are shown in FIG. 4, which is a plot of MgO texture as a function of the number of SDP coatings for the two solutions. Square symbols represent average out-of-plane texture and circles represent in-plane texture. The inset shows the out-of-plane texture as a function of RMS roughness together with the data taken from Matias et al. in Mater. Res. Soc. Symp. Proc., edited by Barnes et al., vol. 1001E, Warrendale, Pa., 2007, No. 1001-M04-02. A decrease in the FWHM for the mosaic spreads as a function of SDP coatings. The out of plane texture (lower part of the graph) correlates well with the RMS roughness as measured by the AFM on a 5×5 micrometer area. The inset of FIG. 4 plots these out-of-plane data versus roughness with the previously published data for mechanically polished samples described in Matias et al. in Mater. Res. Soc. Symp. Proc., edited by Barnes et al., vol. 1001E, Warrendale, Pa., 2007, No. 1001-M04-02. This agreement was good, but the in-plane texture did not correlate well with only the roughness values. From this data, the 0.08 M solution had better in-plane texture than the 0.04 M solution, even though the roughness numbers were reversed (see FIG. 2).
  • The SDP prepared substrates were used for creating IBAD templates for superconducting coated conductors. In an embodiment, a layer of YBa2Cu3O7 (YBCO) of 1-3 micrometers in thickness was deposited on the IBAD template. A number of different YBCO deposition techniques were used successfully on these templates, including pulsed laser deposition (PLD), reactive coevaporation (RCE), and MOCVD. FIG. 1 a shows a 1.2 micrometer YBCO layer deposited by PLD on the IBAD/SDP template with a SrTiO3 buffer layer. For this sample, the critical current, Jc, at 75K in self field (SF) was measured to be 2.85 MA/cm2. For comparison, a RCE YBCO film of 1 micrometer was deposited on an IBAD/SDP template and the Jc at 75K (SF) was 4 MA/cm2 without a buffer layer. These Jc values match or exceed the best undoped YBCO samples made by PLD on single crystal substrates (see: Foltyn et al., Nat. Mater., 2007, vol. 6, p. 631).
  • Another aspect of this invention relates to other benefits that are afforded by using a rough substrate and coating with a first solution and then with a second solution. A benefit relates to certain properties of an IBAD-MgO layer deposited on the topmost of the metal oxide layers. A surface roughness less than 1 nm RMS is not required.
  • Certain benefits in grain alignment were found when IBAD-MgO was deposited on yttrium oxide, which was applied by solution deposition planarization on a rough substrate, wherein a two solution process was used for deposition of the yttrium oxide. In particular, it was found that the in-plane texture of an IBAD-MgO layer deposited on the topmost layer formed from a coating process using two solutions of yttrium oxide was superior compared to a process involving the use of only one 0.4 M solution. FIG. 5 a shows a plot of out of plane texture of IBAD-MgO vs. RMS roughness, and FIG. 5 b shows a plot of in plane texture of IBAD-MgO vs. RMS roughness. The plots compare the in plane texture of the IBAD-MgO layers deposited on a variety of surfaces. One of the surfaces is a mechanically polished substrate (open circles). Another surface is formed when a 0.4 M solution of yttrium acetate was used for solution deposition planarization (red squares), and the surface roughness RMS is shown on the x-axis. Another surface is formed when a 0.08 M solution of yttrium acetate was used for solution deposition planarization (gray squares), the surface roughness also shown on the x-axis. The in plane texture of the IBAD-MgO layer appears to be better for the lower molarity solution, and is best when two solutions (diamond), a first solution of 0.4 M, and a second solution of 0.08 M, are used. The plot also indicates that the lower molarities (0.08 M) provide a better in plane texture than the higher molarity coating (0.4 M). At higher surface roughness, the lower molarity coating is a good choice.
  • Thus, the in plane texture for IBAD-MgO deposited on yttrium oxide was best for a process wherein a first solution of 0.4 M yttrium oxide precursor (yttrium acetate, for example) was used first, and then a second solution of lower molarity (0.08 M yttrium oxide precursor, yttrium acetate).
  • In summary, the invention of solution deposition planarization may be used for smoothing substrates in long lengths with resulting RMS roughness less than 1 nm. With the appropriate solution deposited layers, these planarized substrates can be used directly for IBAD-MgO texturing with very high quality and then for deposition of very high Jc-cuprate superconductors.
  • Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations upon the scope of the invention, except as and to the extent that they are included in the accompanying claims. For example, metal oxides besides yttrium oxide may be used instead of yttrium oxide, or in mixtures with yttrium oxide. These other metal oxides include aluminum oxide, titanium oxide, zirconium oxide, hafnium oxide, and rare earth metal oxides such as erbium oxide. A mixture of aluminum oxide with yttrium oxide may also be used. In addition, the invention has thus far been described using two solutions of two different concentrations. It should be understood that the method may be expanded by using three solutions of different molarities, wherein the first solution has a concentration greater than the second solution and the second solution has a concentration greater than the third solution. The method can be expanded to the use of four solutions wherein the first has the highest concentration of the metal oxide precursor, the second having a lower concentration than the first solution with the same precursor, the third solution having a concentration lower than the second, and the fourth a lower concentration than the third. This can be expanded for any number ‘n’ of solutions where the concentration decreases sequentially to the nth solution which has the lowest concentration of the metal oxide precursor. The invention also applies the preparation of metal oxynitride coatings.
  • In another embodiment, titanium dioxide and zirconium dioxide coatings were prepared to planarize unpolished aluminum plate to enable integrated electronics deposition atop the insulating TiO2 or ZrO2 top surface. Solutions of 0.15 M concentration and then 0.05M concentration (a) titanium isopropoxide in isopropanol or (b) zirconium butoxide in isopropanol were subsequently dip coated, using eight layers of each concentration, dried at 300° C. for 1 minute, and subsequently annealed in air at 450° C. for 10 minutes, atop 30 cm wide aluminum plates. The coatings reduced the initial 5 micron-scale roughness to less than 100 nm RMS after annealing. The TiO2 or ZrO2 coated aluminum was subsequently used as an insulating substrate for printed electronic circuit boards, in which the deposited conductive metal traces were then electrically insulated from the rough aluminum substrate via the planarization layers.

Claims (19)

What is claimed is:
1. A process for planarizing a substrate, comprising:
providing a substrate having a surface roughness greater than 3 nm RMS,
providing a first solution comprising a first concentration of yttrium oxide precursor in a solvent,
applying a coating of the solution to the rough surface,
heating the coated substrate under conditions sufficient to evaporate the solvent and convert the solution of yttrium oxide precursor to a layer of yttrium oxide on the substrate,
repeating the steps of applying a coating of the first solution to the rough surface and heating, thereby forming a plurality of layers of yttrium oxide on the substrate, the plurality comprising a surface roughness of less than 3 nm RMS but greater than 1 nm RMS,
providing a second solution comprising a second concentration of yttrium precursor, the second concentration lower than the first concentration,
applying a coating of the second solution on the layer of yttrium oxide,
heating the coated substrate to evaporate the solvent and leave a second layer of yttrium oxide on the substrate,
repeating the steps of applying a coating of the second solution and heating until a planarized substrate having plurality of layers of yttrium oxide deposited thereon with a surface roughness less than 1 nm RMS.
2. The process of claim 1, wherein the first concentration of yttrium oxide precursor is 0.4M.
3. The process of claim 1, wherein the second concentration of yttrium oxide precursor is 0.08M.
4. The process of claim 1, wherein the substrate has a surface roughness of at least 20 nm RMS.
5. The process of claim 1, wherein the substrate has a surface roughness of at least 30 nm RMS.
6. The process of claim 1, wherein the substrate has a surface roughness of at least 40 nm RMS.
7. The process of claim 1, wherein the substrate has a surface roughness of at least 50 nm RMS
8. The process of claim 1, wherein the surface roughness comprising yttrium oxide is less than 0.9 nm RMS.
9. The process of claim 1, wherein the ratio of the concentration of the first solution to the concentration of the second solution is at least 2.0.
10. The process of claim 1, wherein the ratio of the concentration of the first solution to the concentration of the second solution is at least 3.0.
11. The process of claim 1, wherein the ratio of the concentration of the first solution to the concentration of the second solution is at least 4.0.
12. The process of claim 1, wherein the ratio of the concentration of the first solution to the concentration of the second solution is at least 5.0.
13. The process of claim 1, wherein the surface roughness comprising yttrium oxide is less than 0.6 nm RMS.
14. A process for planarizing a substrate, comprising:
providing a substrate having a rough surface,
providing a first solution comprising a first concentration of a metal oxide precursor in a solvent, the metal oxide chosen from the group of rare earth oxides, silicon oxide, hafnium oxide, titanium oxide, zirconium oxide, aluminum oxide, and a mixture of yttrium oxide and aluminum oxide,
applying a coating of the solution to the substrate surface,
heating the coated substrate under conditions sufficient to evaporate the solvent and convert the solution of metal oxide precursor to a layer of metal oxide on the substrate,
repeating the steps of applying a coating of the first solution to the substrate surface and heating, thereby forming a plurality of layers of metal oxide on the substrate, the plurality comprising a surface roughness of greater than 1 nm RMS,
providing a second solution comprising a second concentration of yttrium precursor, the second concentration lower than the first concentration,
applying a coating of the second solution on the layer of metal oxide,
heating the coated substrate to evaporate the solvent and leave a second layer of metal oxide on the substrate,
repeating the steps of applying a coating of the second solution and heating until a planarized substrate having plurality of layers of metal oxide deposited thereon with a surface roughness less than 1 nm RMS.
15. The method of claim 14, wherein said rare earth oxides are chosen from erbium oxide.
16. A method for preparing a layered article, comprising:
providing a substrate having a rough surface,
providing a first solution comprising a first concentration of a metal oxide precursor in a solvent,
applying a coating of the solution to the rough surface,
heating the coated substrate under conditions sufficient to evaporate the solvent and convert the solution of metal oxide precursor to a layer of metal oxide on the substrate,
repeating the steps of applying a coating of the first solution to the rough surface and heating, thereby forming a plurality of layers of metal oxide on the substrate,
providing a second solution comprising a second concentration of metal oxide precursor, the second concentration lower than the first concentration,
applying a coating of the second solution on the layer of metal oxide,
heating the coated substrate to evaporate the solvent and leave a layer of metal oxide on the substrate,
repeating the steps of applying a coating of the second solution and heating,
depositing a layer of biaxially-textured IBAD-MgO on the metal oxide.
17. The method of claim 16, wherein the metal oxide is yttrium oxide, a rare earth metal oxide, or a mixture of yttrium oxide and aluminum oxide.
18. The method of claim 16, wherein the first solution comprises 0.4 M yttrium acetate.
19. The method of claim 17, wherein the second solution comprises 0.08 M yttrium acetate.
US13/168,093 2010-06-29 2011-06-24 Solution deposition planarization method Abandoned US20120040100A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/168,093 US20120040100A1 (en) 2010-06-29 2011-06-24 Solution deposition planarization method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US35973310P 2010-06-29 2010-06-29
US13/168,093 US20120040100A1 (en) 2010-06-29 2011-06-24 Solution deposition planarization method

Publications (1)

Publication Number Publication Date
US20120040100A1 true US20120040100A1 (en) 2012-02-16

Family

ID=45441502

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/168,093 Abandoned US20120040100A1 (en) 2010-06-29 2011-06-24 Solution deposition planarization method

Country Status (2)

Country Link
US (1) US20120040100A1 (en)
WO (1) WO2012005977A1 (en)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013155220A1 (en) * 2012-04-13 2013-10-17 Applied Materials, Inc. Ceramic coated ring and process for applying ceramic coating
DE102013214447B3 (en) * 2013-07-24 2014-11-20 Bruker Hts Gmbh Band-shaped, superconducting element with improved self-protection in quenching
US20140363582A1 (en) * 2013-06-11 2014-12-11 Korea Electrotechnology Research Institute Method of preparing yttria solution for buffer layer of substrate
US9034199B2 (en) 2012-02-21 2015-05-19 Applied Materials, Inc. Ceramic article with reduced surface defect density and process for producing a ceramic article
US9090046B2 (en) 2012-04-16 2015-07-28 Applied Materials, Inc. Ceramic coated article and process for applying ceramic coating
US9212099B2 (en) 2012-02-22 2015-12-15 Applied Materials, Inc. Heat treated ceramic substrate having ceramic coating and heat treatment for coated ceramics
US9343289B2 (en) 2012-07-27 2016-05-17 Applied Materials, Inc. Chemistry compatible coating material for advanced device on-wafer particle performance
US9394615B2 (en) 2012-04-27 2016-07-19 Applied Materials, Inc. Plasma resistant ceramic coated conductive article
US9604249B2 (en) 2012-07-26 2017-03-28 Applied Materials, Inc. Innovative top-coat approach for advanced device on-wafer particle performance
US9735318B2 (en) 2015-02-10 2017-08-15 iBeam Materials, Inc. Epitaxial hexagonal materials on IBAD-textured substrates
US9865434B2 (en) 2013-06-05 2018-01-09 Applied Materials, Inc. Rare-earth oxide based erosion resistant coatings for semiconductor application
US10160660B1 (en) 2014-05-28 2018-12-25 National Technology & Engineering Solutions Of Sandia, Llc Vanadium oxide for infrared coatings and methods thereof
US10243105B2 (en) 2015-02-10 2019-03-26 iBeam Materials, Inc. Group-III nitride devices and systems on IBAD-textured substrates
US10501843B2 (en) 2013-06-20 2019-12-10 Applied Materials, Inc. Plasma erosion resistant rare-earth oxide based thin film coatings
US11047035B2 (en) 2018-02-23 2021-06-29 Applied Materials, Inc. Protective yttria coating for semiconductor equipment parts
USRE49869E1 (en) 2015-02-10 2024-03-12 iBeam Materials, Inc. Group-III nitride devices and systems on IBAD-textured substrates

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102955595B (en) * 2011-08-21 2016-05-25 宸鸿科技(厦门)有限公司 Sensing method of touch control and device
BE1020692A3 (en) 2012-05-16 2014-03-04 Prayon Sa METHOD FOR MANUFACTURING COMPOSITE MATERIAL
CN104233297B (en) * 2014-09-17 2016-11-30 上海大学 The quick leveling method of high-temperature superconductor band substrate
CN113476157A (en) * 2021-07-08 2021-10-08 上海森艺医疗科技有限公司 Zirconia dental crown and preparation method thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5259885A (en) * 1991-04-03 1993-11-09 American Superconductor Corporation Process for making ceramic/metal and ceramic/ceramic laminates by oxidation of a metal precursor
US5470820A (en) * 1991-05-06 1995-11-28 Hauser Chemical Research, Inc. Electroplating of superconductor elements
US20040248014A1 (en) * 2003-01-30 2004-12-09 West Robert C. Electrolyte including polysiloxane with cyclic carbonate groups
US7510641B2 (en) * 2003-07-21 2009-03-31 Los Alamos National Security, Llc High current density electropolishing in the preparation of highly smooth substrate tapes for coated conductors
EP1805817B1 (en) * 2004-10-01 2016-11-16 American Superconductor Corporation Thick superconductor films with improved performance

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Guillen et al "Leveling Effect of Sol-gel SiO2 Coatings onto Metallic Foil Substrates" Surface and Coatings Technology 138 (2001) 205-210. *
Hu et al. "The Surface Morphology of Ba0.65Sr0.35TiO3 Thin Film by Sol-Gel Method" Integrated Ferroelectronics, 72, 1-11, 2005. *
Lu et al "Development of textured MgO Templates on Nonmetallic Flexible Ceraflex" Applied Physics Letters 89, 132505-1-132505-3 (2006). *

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10336656B2 (en) 2012-02-21 2019-07-02 Applied Materials, Inc. Ceramic article with reduced surface defect density
US9034199B2 (en) 2012-02-21 2015-05-19 Applied Materials, Inc. Ceramic article with reduced surface defect density and process for producing a ceramic article
US11279661B2 (en) 2012-02-22 2022-03-22 Applied Materials, Inc. Heat treated ceramic substrate having ceramic coating
US10364197B2 (en) 2012-02-22 2019-07-30 Applied Materials, Inc. Heat treated ceramic substrate having ceramic coating
US9212099B2 (en) 2012-02-22 2015-12-15 Applied Materials, Inc. Heat treated ceramic substrate having ceramic coating and heat treatment for coated ceramics
WO2013155220A1 (en) * 2012-04-13 2013-10-17 Applied Materials, Inc. Ceramic coated ring and process for applying ceramic coating
US9090046B2 (en) 2012-04-16 2015-07-28 Applied Materials, Inc. Ceramic coated article and process for applying ceramic coating
US9394615B2 (en) 2012-04-27 2016-07-19 Applied Materials, Inc. Plasma resistant ceramic coated conductive article
US9604249B2 (en) 2012-07-26 2017-03-28 Applied Materials, Inc. Innovative top-coat approach for advanced device on-wafer particle performance
US9343289B2 (en) 2012-07-27 2016-05-17 Applied Materials, Inc. Chemistry compatible coating material for advanced device on-wafer particle performance
US9865434B2 (en) 2013-06-05 2018-01-09 Applied Materials, Inc. Rare-earth oxide based erosion resistant coatings for semiconductor application
US10734202B2 (en) 2013-06-05 2020-08-04 Applied Materials, Inc. Rare-earth oxide based erosion resistant coatings for semiconductor application
US20140363582A1 (en) * 2013-06-11 2014-12-11 Korea Electrotechnology Research Institute Method of preparing yttria solution for buffer layer of substrate
US11680308B2 (en) 2013-06-20 2023-06-20 Applied Materials, Inc. Plasma erosion resistant rare-earth oxide based thin film coatings
US10501843B2 (en) 2013-06-20 2019-12-10 Applied Materials, Inc. Plasma erosion resistant rare-earth oxide based thin film coatings
US11053581B2 (en) 2013-06-20 2021-07-06 Applied Materials, Inc. Plasma erosion resistant rare-earth oxide based thin film coatings
US9640979B2 (en) 2013-07-24 2017-05-02 Bruker H I S GmbH Band-shaped superconducting element with improved self-protection in case of quenching
DE102013214447B3 (en) * 2013-07-24 2014-11-20 Bruker Hts Gmbh Band-shaped, superconducting element with improved self-protection in quenching
EP2830107A1 (en) 2013-07-24 2015-01-28 Bruker HTS GmbH Tape-shaped, superconducting element with improved self-protection fields in case of quenching
US10889506B2 (en) 2014-05-28 2021-01-12 National Technology & Engineering Solutions Of Sandia, Llc Vanadium oxide for infrared coatings and methods thereof
US10160660B1 (en) 2014-05-28 2018-12-25 National Technology & Engineering Solutions Of Sandia, Llc Vanadium oxide for infrared coatings and methods thereof
US9735318B2 (en) 2015-02-10 2017-08-15 iBeam Materials, Inc. Epitaxial hexagonal materials on IBAD-textured substrates
US10546976B2 (en) 2015-02-10 2020-01-28 iBeam Materials, Inc. Group-III nitride devices and systems on IBAD-textured substrates
US10243105B2 (en) 2015-02-10 2019-03-26 iBeam Materials, Inc. Group-III nitride devices and systems on IBAD-textured substrates
USRE49869E1 (en) 2015-02-10 2024-03-12 iBeam Materials, Inc. Group-III nitride devices and systems on IBAD-textured substrates
US11047035B2 (en) 2018-02-23 2021-06-29 Applied Materials, Inc. Protective yttria coating for semiconductor equipment parts

Also Published As

Publication number Publication date
WO2012005977A1 (en) 2012-01-12

Similar Documents

Publication Publication Date Title
US20120040100A1 (en) Solution deposition planarization method
US10446294B2 (en) Coated conductor high temperature superconductor carrying high critical current under magnetic field by intrinsic pinning centers, and methods of manufacture of same
Sheehan et al. Solution deposition planarization of long-length flexible substrates
US6383989B2 (en) Architecture for high critical current superconducting tapes
RU2384907C1 (en) Superconducting thin-film material and method of making said material
RU2332737C2 (en) Superconductive wire and method of its manufacturing
US20120028810A1 (en) Method for depositing oxide thin films on textured and curved metal surfaces
JP5799081B2 (en) Thick oxide film with single layer coating
WO2006082747A1 (en) Superconducting thin film material, superconducting wire rod and methods for manufacturing such superconducting thin film material and superconducting wire rod
Cai et al. Completely etch-free fabrication of multifilamentary coated conductor using inkjet printing and electrodeposition
Qiao et al. Scale up of coated conductor substrate process by reel-to-reel planarization of amorphous oxide layers
DE60031784T2 (en) IMPROVED HIGH TEMPERATURE SUPER PLATE COATED ELEMENTS
Haugan et al. Flux pinning of Y-Ba-Cu-O films doped with BaZrO 3 nanoparticles by multilayer and single target methods
Narayanan et al. Aqueous chemical solution deposition of lanthanum zirconate and related lattice-matched single buffer layers suitable for YBCO coated conductors: A review
Zhou et al. Highly efficient colloid–solution deposition planarization of Hastelloy substrate for IBAD-MgO film
Liu et al. Development of long REBCO coated conductors by PLD-REBCO/Sputter-CeO 2/IBAD-MgO at SJTU and SSTC
Arda et al. Residual stress analysis of multi-layered buffer layers on Ni substrate for YBCO coated conductor
Li et al. Fast growth processes of buffer layers for YBCO coated conductors on biaxially-textured Ni tapes
Lin et al. Improved epitaxial texture of thick YBa2Cu3O7− δ/GdBa2Cu3O7− δ films with periodic stress releasing
JP5881107B2 (en) Method for introducing nanoscale crystal defects into high temperature superconducting oxide thin films
Nie et al. Biaxially textured MgO buffer layer on flexible metal template for coated conductor
Develos-Bagarinao et al. Enhanced flux pinning in MOD YBa2Cu3O7− δ films by ion milling through anodic alumina templates
Chen et al. Growth of biaxially textured CeO2/YSZ/CeO2 and SrTiO3 buffer layers on textured Ni substrates by pulsed laser deposition
Endo et al. New growth approach of high-quality oxide thin films for future device applications: Independent control of supersaturation and migration
Araki et al. Growth mechanism during firing process of single-coated thick YBCO films by TFA-MOD

Legal Events

Date Code Title Description
AS Assignment

Owner name: LOS ALAMOS NATIONAL SECURITY, LLC, NEW MEXICO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MATIAS, VLADIMIR;SHEEHAN, CHRISTOPHER J;SIGNING DATES FROM 20110921 TO 20110929;REEL/FRAME:027142/0879

AS Assignment

Owner name: U.S. DEPARTMENT OF ENERGY, DISTRICT OF COLUMBIA

Free format text: CONFIRMATORY LICENSE;ASSIGNOR:LOS ALAMOS NATIONAL SECURITY;REEL/FRAME:027455/0739

Effective date: 20110906

AS Assignment

Owner name: SANDIA CORPORATION, NEW MEXICO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:IHLEFELD, JON FREDRICK;CLEM, PAUL GILBERT;SIGNING DATES FROM 20120809 TO 20120827;REEL/FRAME:028915/0131

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION